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Old 03-27-2008, 12:19 AM   #22 (permalink)
s2man
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Join Date: Jan 2008
Location: Kansas City, MO
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Porthos - '96 Chevrolet Cavalier
90 day: 31.3 mpg (US)
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Quote:
Originally Posted by fabrio. View Post
For an correctly reading of BSFC, the map it must be without the torque value, but with the % of PME max(pressure, average real).
I think the torque can be as useful as the engine pressure (BMEP). Yes, there are losses due to friction and respiration. But I think the torque Y axis still gives us a good measurement of force, since higher pressure in the cylinder will result in higher torque. BSFC maps seem to use torque and pressure interchangeably.

Quote:
Originally Posted by fabrio. View Post
For to go the engine in the optimal fuel economy (in this case by 250 gHP/H), it is necessary the needed load. In normal operation, in flat road, in the last gear and without acceleration, it is impossible go to optimal area of BSFC.
Yes, we are talking about accelerating, not normal operation. But at normal operation, we should also be able to change the engine load slightly through gearing. Higher gears will make the engine turn slower, needing more open throttle and higher load to put out the same power.

This thread has me thinking about what I should do next. I have parts for two tests: a full rear-body lip for air-flow separation testing, and an adjustable throttle limiter for acceleration tests at different throttle positions. I was planning to do the aero test first, but now the throttle position has my mind occupied. I watched the LOD out put on the ScanGauge today, and I can not believe I'm reaching such high loads at low throttle positions.
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